JP2006071503A - Wheel for timepiece and timepiece - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wheel for a timepiece with high dimensional precision by a slippage structure having a stable slippage torque and a timepiece having it. <P>SOLUTION: The wheel for a timepiece 1 is constituted by allowing a gear 2 and a shaft member 3 to become engaged through spring sections 4. The spring sections 4 are formed at three sites so that they extend inwardly from the perimeter of the gear 2 like long arches to form space at the center 5 of the gear 2 allowing the shaft member 3 to pass through. The spring sections 4 and the shaft member 3 become engaged through a spring force of the spring sections 4. The gear 2 having the spring sections 4 is manufactured by electroforming with high precision using a high-precision pattern drawn on a photomask. The gear 2 having the spring sections 4 with long spring length and a stable spring force can be thereby manufactured, providing a slippage torque in the slippage structure 7 with stability. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a timepiece car and a timepiece.

For example, in a correction wheel train for correcting time and a winding wheel train for winding a mainspring used in a timepiece, a predetermined mechanism may be provided with a slip mechanism.
As the slip mechanism, during hand movement, the small gear and the shaft member that make up the car are engaged with each other by the spring force of the spring provided inside the gear, and when the time is adjusted or the mainspring is wound There is a mechanism that slips between the spring portion and the shaft member when the gear is forcibly rotated with a torque of a certain level or more by a crown operation such as.
As another slip mechanism, a mechanism for correcting the time in one hour steps is known (see, for example, Patent Document 1). This slip mechanism has a jumper gear consisting of a small gear and a jumper pinion that rotates at the center of the jumper gear, and at the time of hand movement, the spring portion provided inside the jumper gear is engaged with the jumper pinion, This is a mechanism in which when the time is adjusted, the spring portion jumps between the gear teeth of the jumper kana in steps, and the jumper gear and the jumper kana slip.
And as a manufacturing method of the small gear provided with the spring part used for these slip mechanisms, a method of manufacturing by a plurality of processes such as press working and tooth splitting by cutting is known (for example, see Patent Document 2). ).

Japanese Examined Patent Publication No.7-111463 (pages 2 to 4 and FIG. 1) JP 2003-194964 A (page 3, FIG. 2)

However, in Patent Document 2, since the spring portion is formed by press working, the shape of the spring portion is limited by the restriction of the strength surface of the punch or die. Accordingly, there is a problem that a sufficient spring length cannot be obtained with a small gear and the slip torque is not stable.
Further, since the manufacturing is performed in a plurality of steps, errors are accumulated. Poor dimensional accuracy due to variations in the shape of the spring part causes eccentricity between the tooth profile and the slip shaft, which causes a displacement of the indicated position and causes the slip torque to become unstable.

  An object of the present invention is to provide a timepiece wheel having a dimensional accuracy having a slip mechanism with stable slip torque and a timepiece having the same.

  The timepiece wheel of the present invention includes a gear provided with a spring portion, a shaft member that is engaged with a central portion of the gear and that is held by the spring force of the spring portion, and a spring of the spring portion And a slip mechanism for generating a slip between the gear and the shaft member against a force, wherein the gear is formed by electroforming.

  According to this invention, since the spring part is manufactured by direct electroforming, the dimensional accuracy of the spring part is improved as compared with the conventional press-processed manufacture. Therefore, by combining the gear provided with the spring portion and the shaft member, a timepiece wheel having a slip mechanism having a stable slip torque can be obtained.

In the present invention, the electroformed material preferably contains Ni and Co.
In the present invention, the gear and the spring portion contain Ni and Co, thereby increasing the hardness and improving the wear resistance.

In the present invention, the gear is provided with a master surface on which the surface of the master die used for electroforming is transferred, and a photo surface on the photomask side used in a photolithography process during electroforming,
Positioning of the gear and the shaft member is performed by a portion of the side surface of the spring portion that is closer to the photo surface and a tapered shaft-side engaging portion provided on the shaft member. preferable.
According to the present invention, in the engaging portion provided in the shaft member, the inclination of the taper is larger than the inclination of the side surface of the spring portion, and the side surface portion to which the photomask pattern is faithfully transferred contacts the taper portion. Thus, a timepiece wheel with high assembly accuracy can be obtained.

In the present invention, a plurality of the spring portions are formed, the engaging portions of the respective spring portions are formed as curved surfaces, and the curvature radius of the curved surface is larger than the radius of the shaft side engaging portion provided in the shaft member. Is preferred.
According to this invention, since the radius of curvature of the curved surface of the spring portion is larger than the radius of the shaft side engaging portion, the shaft side engaging portion is smoothly engaged at one place on the curved surface of the spring portion. Further, the wear of the engaging portions is small, and even if some wear occurs, the shaft member can be stably fixed in one place without being displaced. Therefore, it is possible to obtain a timepiece wheel provided with a slip mechanism with more stable slip torque.

In this invention, it is preferable that the said gearwheel is provided with the guide part which regulates position shift with the said shaft member.
According to this invention, since the gear is provided with the guide portion, there is no fear that the shaft member is displaced from the center of the gear. Therefore, the shaft member can be stably positioned, a timepiece wheel with higher assembly accuracy can be obtained, and the slip torque can be stabilized.

The timepiece of the present invention includes the timepiece car described above.
According to the present invention, a timepiece having a slip mechanism having a stable slip torque can be obtained by using the timepiece wheel having high assembly accuracy in the timepiece.

  According to the present invention, there is an effect that it is possible to obtain a timepiece wheel having a high dimensional accuracy provided with a slip mechanism having a stable slip torque and a timepiece including the same.

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be specifically described with reference to the drawings.
FIG. 1 and FIG. 2 are a plan view showing a timepiece car 1 according to this embodiment and an enlarged view showing a main part of the timepiece car 1. FIG. 3 is a process diagram for explaining a method of manufacturing the gear 2 constituting the timepiece wheel 1.

In FIG. 1, the timepiece wheel 1 is configured by an engagement portion 6 provided on a spring portion 4 of a gear 2 and a shaft side engagement portion 50 provided on a shaft member 3 engaging each other. . The spring portion 4 is formed in three arch shapes inward from the outer periphery of the gear 2, and forms a space through which the shaft member 3 passes in the central portion 5 of the gear 2.
Here, when a certain torque or more is applied to the gear 2, the gear 2 and the shaft member 3 slip each other. The magnitude of this torque is determined by the spring force of the spring portion 4. The spring force is changed by changing the material and shape of the spring portion 4. As described above, the timepiece wheel 1 includes the slip mechanism 7 that generates a slip between the gear 2 and the shaft member 3 against the spring force of the spring portion 4. That is, the slip mechanism 7 includes the spring portion 4 on the gear 2 side and the shaft-side engaging portion 50 of the shaft member 3 that engages with the engaging portion 6 of the spring portion 4.

FIG. 2 shows an enlarged view of a portion where the shaft member 3 and the spring portion 4 of the gear 2 are engaged.
The engaging portion 6 of the spring portion 4 is a portion that engages with the shaft-side engaging portion 50 having a circular cross section, and is formed as a concave curved surface with respect to the shaft-side engaging portion 50. The radius of curvature of the curved surface is set to be larger than the radius of the shaft side engaging portion 50, and the shaft side engaging portion 50 is engaged at one place in each engaging portion 6. Therefore, the shaft side engaging portion 50 is engaged at three positions by the three spring portions 4.

  FIG. 3 is a partial cross-sectional view for explaining the manufacturing process of this embodiment. Here, a cross-sectional view in the vicinity of where the two gears 2 are formed is schematically shown. Steps (A) to (C) are photolithography steps.

  In the step (A), an ultraviolet curable negative type resist 11 is applied to the surface of the electroformed mother die 10. The thickness of the resist 11 to be applied is several tens of μm thicker than the thickness of the gear 2. Here, the thickness of the gear 2 to be formed is 0.1 mm. However, in FIG. 3, the thickness of the resist 11 and the gear 2 is exaggerated greatly in order to facilitate understanding of the cross-sectional shape.

  Stainless steel is used for the mother die 10. The shape of the surface 15 of the mother die 10 is transferred to the surface of the gear 2 by electroforming. Hereinafter, the surface of the gear 2 to which the shape of the surface 15 of the mother die 10 is transferred is referred to as a mother die surface 40. In this embodiment, since the surface of the mother die surface 40 is a mirror surface, the surface of the mother die 10 is mirror-finished in advance.

  Next, the resist 11 is baked by ultraviolet rays using the photomask 20 in the step (B). At this time, the pattern 2P of the photomask 20 shields the portion of the gear 2 from electroforming, and the resist 11 corresponding to this portion is prevented from being cured. On the contrary, the central portion 5 of the gear 2 is cured by the ultraviolet light transmission region 24N. In addition, a portion that becomes a margin around the gear 2 is cured by the transmission region 27N.

Step (C) is a development step, and the uncured resist portion is removed. Here, (C) shows a hardened resist portion 31N which becomes the central portion 5 after electroforming, and a resist portion 32N corresponding to the blank portion.
When the uncured portion is removed, the side surfaces 22 of the resist portions 31N and 32N are not perpendicular to the mother die 10 but are inclined. Specifically, the side surface 22 is inclined so that the resist portions 31N and 32N taper from the surface side of the photomask 20 toward the mother die 10, and the inclination is about 3 ° to 6 °.

Step (D) is an electroforming step. The metal electroforming material 32 used for electroforming is deposited on the mold portion of the mother die 10 other than the resist portions 31N and 32N. The electroformed material 32 is deposited until it becomes thicker than the resist 11.
In this embodiment, as the electroformed material 32, an alloy of 80% Ni and 20% Co is used. As the electroforming material 32, Ni alone or other metal or alloy may be used.
In addition, the surface of the mother die 10 is preliminarily treated with a mobilization treatment or a passivation treatment before the electroforming process so that the formed gear 2 can be peeled off with an appropriate force. 10 can be adjusted.

  In the step (E), the surface is polished to the required thickness of the gear 2 and planarized. Hereinafter, this polished surface is referred to as a photo surface 25. Here, the surface of the photo surface 25 is finished to be a mirror surface in the same manner as the surface 15 on the mother die 10 side.

In step (F), the resist portion 31N of the central portion 5 and other unnecessary resist portions 32N are removed. In this state, the gear 2 is in close contact with the mother die 10 with an appropriate close contact force.
Here, the side surface portion 24 of the tooth tip of the gear 2 has an inclination similar to the side surface 23 of the central portion 5 (in the drawing, exaggeratedly shown). There is practically no effect on the meshing with other cars.

  Finally, in the step (G), the gear 2 is peeled off. The gear 2 can be peeled off by deforming the matrix 10 or the like, and the transfer sheet can be peeled off by being attached from the top surface.

FIG. 4 shows a cross-sectional view of the engaging portion between the gear 2 and the shaft member 3 of the timepiece wheel 1 in this embodiment.
The side surface 23 of the spring portion 4 of the gear 2 obtained by the above-described photolithography process is formed based on the side surface 22 of the resist 31N, and thus has the same inclination as the side surface 22. In this case, the side surface portion 42 on the photo surface 25 side is a position close to the pattern 2P formed on the photomask 20, and the shape of the pattern 2P is reflected more accurately, so that the dimensional accuracy is good. Therefore, when alignment is performed on the side surface portion 42, the dimensional accuracy of the timepiece wheel 1 is also improved.
When the thickness of the gear 2 of the present embodiment is 0.1 mm, the manufacturing error of the hole diameter of the central portion 5 of the photo surface 25 is about ± 2.5 μm, and the master surface 40 is about ± 5 μm. As the thickness of the gear 2 increases, the manufacturing error of the master surface 40 increases and the dimensional accuracy also decreases.
The shaft side engaging portion 50 of the shaft member 3 is formed in a tapered shape having a large diameter on the press-fitting side into which the gear 2 is press-fitted. Here, the angle of the taper shape is larger than the inclination of the side surface 23 and is formed to be 6 ° or more.

Below, the engagement method of the gearwheel 2 and the shaft member 3 is described.
When the gear 2 is engaged with the shaft member 3, the spring portion 4 is elastically deformed and the central portion 5 is expanded. After the engagement, the spring portion 4 is engaged by pushing the shaft member 3 due to elasticity. Engagement is performed from the mold surface 40 side. Here, since the diameter on the engagement side is a taper shape and the diameter of the matrix surface 40 is small, it is easy to engage by chamfering a portion having a large taper shape diameter. Since the inclination of the side surface 23 is smaller than the inclination of the shaft side engaging portion 50, the matrix surface 40 side does not contact the shaft side engaging portion 50, and after the engagement, the side surface portion 42 on the photo surface 25 side and the shaft Positioning is performed by the side engaging portion 50.

    A timepiece is obtained by incorporating the timepiece car 1 obtained as described above.

According to such an embodiment, there are the following effects.
(1) Since the spring portion 4 is manufactured by direct electroforming based on the pattern 2P of the photomask 20 with high dimensional accuracy, the dimensional accuracy of the spring portion 4 is compared with the conventional case manufactured by press working. Can be improved. Therefore, when the gear 2 provided with the spring portion 4 and the shaft member 3 are combined, the timepiece wheel 1 of the slip mechanism 7 with stable slip torque can be obtained. Further, the variation in shape between the spring portions 4 is reduced, the amount of bending of each spring portion 4 can be made the same, and the eccentricity of the gear 2 with respect to the shaft member 3 can be reduced.

(2) In particular, since the spring portion 4 is formed by electroforming rather than press working using a punch or die, the corner R formed at the base end portion of the spring portion 4 can also be reduced. The spring portion 4 can be lengthened by the amount of small R, and the spring force can be stabilized.

(3) Since the gear 2 and the spring portion 4 contain Ni and Co, the hardness can be increased and the wear resistance can be improved. Therefore, the dimensional accuracy after repeated use can be improved, and a stable slip torque can be obtained over time.

(4) In the shaft-side engaging portion 50 provided with the shaft member 3, the side surface portion 42 on which the inclination of the taper is larger than the inclination of the side surface 23 of the spring portion 4 and the pattern 2P of the photomask 20 is faithfully transferred, The taper part is brought into contact with and engaged. Therefore, the variation in the hole diameter of the central portion 5 is small, the variation in the deflection amount of the spring portion 4 can be reduced, and the slip torque can be stabilized.

(5) Since the radius of curvature of the curved surface of the spring part 4 is larger than the radius of the shaft side engaging part 50 and is smoothly engaged at one place on the curved surface of the shaft member 3 and the spring part 4, the mutual engagement There is little wear of the part, and even if some wear occurs, the position of the shaft member 3 is not displaced and can be stably fixed at one place. Therefore, the timepiece wheel 1 having a slip mechanism with more stable slip torque can be obtained.

(6) Since the mold 2 and the cutter are not required for the production of the gear 2 provided with the spring portion 4, it is possible to produce a small variety of products at low cost.

[Second Embodiment]
Hereinafter, a second embodiment of the present invention will be described with reference to the drawings.
FIG. 5 shows a plan view of the gear 60 of the second embodiment. This embodiment also includes a slip mechanism 7 as in the first embodiment.
The gear 60 includes three spring portions 61 and three guide portions 62 arranged at equal circumferential intervals. The engaging portion 63 at the tip of the spring portion 61 that engages with the shaft member 3 is formed to have a convex curvature with respect to the shaft member 3, contrary to the first embodiment. Engage. The spring portion 61 is formed in a fan shape by dividing it into three spring portions 611, 612, and 613 so as to increase the spring length, and is configured by connecting them.
The guide part 62 is formed from the outer periphery of the gear 60 to a position where it is substantially in contact with the shaft member 3, and restricts the positional deviation (eccentricity) between the shaft member 3 and the gear 60.
Similarly to the first embodiment, the gear 60 of the second embodiment is manufactured by electroforming including a photolithography process, and is similarly engaged with the shaft member 3.

According to such an embodiment, in addition to the effects obtained in the first embodiment, there are the following effects.
(7) The spring portion 61 is composed of three stages of spring portions 611, 612, and 613 from the outside to the inside, and is formed so as to increase the spring length. It can be stabilized.

(8) Since the gear 60 is provided with the guide portion 62, there is no fear that the shaft member 3 is displaced from the center of the gear 60. Therefore, the shaft member 3 can be positioned stably, a timepiece wheel with high assembly accuracy can be obtained, and the slip torque can be stabilized.

[Third Embodiment]
The third embodiment of the present invention will be described below with reference to the drawings.
This embodiment includes a slip mechanism 7 for correcting the time in one hour steps.
FIG. 6 shows a plan view of the jumper gear 70 of the third embodiment.
A jumper pinion 75 provided on the shaft member 3 is rotatably fitted at the center of the jumper gear 70 so as to be substantially in contact therewith. For example, 24 teeth are formed on the jumper kana 75 so that the time can be adjusted every hour. The spring portion 71 is formed with five stages of spring portions 711, 712, 713, 714, and 715 so as to surround the jumper pinion 75 over an approximately 3/4 region of the entire jumper gear 70. The jumper pinion 75 is engaged with the distal end portion 72 of the spring portion 71. A state before the spring portion 71 is bent is shown by a two-dot chain line. By engaging the jumper pinion 75, the spring portion 71 is bent as shown by a solid line. Normally, the tip portion 72 is engaged between the teeth of the jumper pinion 75 by the spring force of the spring portion 71. However, when a torque of a certain level or more is applied, the spring portion 71 is further bent and the tip portion 72 is a jumper pinion. Only the jumper gear 70 rotates by jumping over the 75 teeth, and the hour wheel (not shown) meshing with the jumper pinion 70 is rotated so that the hour hand is adjusted every hour.
Similarly to the first embodiment, the jumper gear 70 of the third embodiment is manufactured by a photolithography process and electroforming.

According to such an embodiment, there are the following effects.
(9) Since the spring part 71 having a shape difficult to press can be easily processed by the photolithography process and electroforming, the length of the spring part 71 can be increased and the low-stress spring part 71 can be formed. Therefore, the durability of the spring portion 71 can be improved.

[Fourth Embodiment]
Hereinafter, a fourth embodiment of the present invention will be described with reference to the drawings. As in the third embodiment, this embodiment includes a slip mechanism 7 for correcting the time in one hour steps.
FIG. 7 shows a plan view of a jumper gear 80 of the fourth embodiment.
A jumper pinion 85 provided on the shaft member 3 is fitted in the center of the jumper gear 80 as in the third embodiment. On one side of the jumper gear 80, a bow-shaped thinned portion 84 is formed, and a rod-shaped first spring portion 81 that is in contact with the jumper pinion 85 is substantially parallel to the bow-shaped chord direction from the outer periphery of the thinned portion 84. Is formed. In addition to the first spring portion 81, another elongated rod-shaped second spring portion 83 is provided in parallel on one side of the first spring portion 81 opposite to the jumper pinion 85. The positional relationship between the two spring portions 81 and 83 is such that the first spring portion 81 is in contact with the second spring portion 83 with the jumper pinion 85 fitted therein, and the tip portion 82 is connected to the teeth of the jumper pinion 85. When jumping over, the spring portion 81 is further bent together with the second spring portion 83. The state of the spring parts 81 and 83 before the jumper kana 85 is fitted is indicated by a two-dot chain line.
Similarly to the first embodiment, the jumper gear 80 of the fourth embodiment is formed by electroforming including a photolithography process.

According to such an embodiment, there are the following effects.
(10) By arranging the two spring portions 81 and 83 in parallel, each of the spring portions 81 and 83 can be bent with low stress, and durability can be improved. In addition, the electroforming including the photolithography process can easily process the rod-shaped spring portions 81 and 83 that are difficult to press.

Note that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
For example, the metal that is the electroforming material can be selected according to the shape of the spring portion and the required wear resistance, and Ni alone or other metals or alloys may be used.
In each of the above-described embodiments, the spring part is formed integrally with the gear. However, a part including the spring part is formed by electroforming including a photolithography process, and a separately manufactured gear is joined later. May be integrated.
Furthermore, the number and shape of the spring portions in each embodiment and the number and shape of the guide portions in the second embodiment can be changed as necessary.

Further, the best configuration, method and the like for carrying out the present invention have been disclosed in the above description, but the present invention is not limited to this. That is, the present invention has been illustrated and described primarily with respect to particular embodiments, but for each embodiment described above without departing from the scope and spirit of the present invention. Various modifications can be made by those skilled in the art in terms of shape, material, quantity, and other detailed configurations.
Therefore, the description limited to the shape, material, etc. disclosed above is an example for easy understanding of the present invention, and does not limit the present invention. The description by the name of the member which remove | excluded the limitation of one part or all of such restrictions is included in this invention.

The top view which shows the timepiece wheel concerning 1st Embodiment of this invention. The enlarged view which shows the principal part of the timepiece car concerning 1st Embodiment. Process drawing which shows the manufacturing method of the gear concerning embodiment of this invention. Sectional drawing of the engaging part of the timepiece wheel concerning 1st Embodiment. The top view which shows the gearwheel concerning 2nd Embodiment of this invention. The top view which shows the gearwheel concerning 3rd Embodiment of this invention. The top view which shows the gearwheel concerning 4th Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Timepiece wheel, 2 ... Gear, 3 ... Shaft member, 4 ... Spring part, 5 ... Center part, 6 ... Spring part engaging part, 7 ... Slip mechanism, 10 ... Master mold, 20 ... Photomask, 23 DESCRIPTION OF SYMBOLS: Side surface of a spring part, 25 ... Photo surface, 32 ... Electroforming material, 40 ... Master-mold surface, 42 ... Side part of the site | part near the photo surface, 50 ... Shaft side engaging part, 62 ... Guide part.

Claims (6)

A gear provided with a spring part;
A shaft member that engages with the central portion of the gear and is held by the spring force of the spring portion;
A slip mechanism for causing a slip between the gear and the shaft member against a spring force of the spring portion;
The timepiece wheel is characterized in that the gear is formed by electroforming. The timepiece car according to claim 1,
A timepiece car characterized in that the electroformed material contains Ni and Co. The timepiece car according to claim 1 or 2,
The gear is provided with a master surface on which the surface of the master die used for electroforming is transferred, and a photo surface on the photomask side used in a photolithography process during electroforming,
The positioning of the gear and the shaft member is performed by a portion of the side surface of the spring portion that is closer to the photo surface and a tapered shaft-side engaging portion provided on the shaft member. Features a watch car. The timepiece car according to any one of claims 1 to 3,
A plurality of the spring portions are formed,
The engaging part of each spring part is formed with a curved surface,
A timepiece wheel characterized in that a radius of curvature of the curved surface is larger than a radius of a shaft side engaging portion provided in the shaft member. The timepiece car according to any one of claims 1 to 4,
2. The timepiece wheel according to claim 1, wherein the gear includes a guide portion that regulates a positional deviation from the shaft member.   A timepiece comprising the timepiece car according to claim 1.

Images